"János is a smart and able boy, but Péter is stupid!"

Translation: János okos és ügyes fiú, de Péter hülye!

[GregorFiedler]

Wouldn't this also be correct? "János egy okos és ügyes fiú, de Péter hülye!"

[RyagonIV]

That is okay. You could also say "de Péter egy hülye" but that wouldn't match the English sentence anymore.

[Patricia460976]

It is now accepted 10 October 2017.

[Tarmil]

Would "Péter pedig hülye" work here?

[vvsey]

Not really. That would relate to an "and" in the English sentence, instead of the "but".

[ilmolleggi]

What about képes for "able": wouldn't that also be correct?

[RyagonIV]

It sounds good. At the least it would be a better translation for "able". Ügyes is more along the lines of "dexterous" or "skilful". (What, in British English "skillful" has just a single l? Jeesh.)

[ilmolleggi]

Cheers for both the answer and the new info on BE ;)